Actually, turns out I used the wrong label. "Ultra" bleach is normally just sodium hypochlorite (but you should always check the label) although more concentrated than the usual 5-6% concentration, so the dilution will be different than the standard instructions.

What I was thinking of are the thicker, splash-resistant kinds of bleach, like Clorox Advantage. That's what I meant when I wrote "ultra". Like scented bleach, they contain additional ingredients that you probably do not want in your drinking water.